Method and apparatus for texturizing yarn



Dec. 11, 1962 P. VAN DlJK METHOD AND APPARATUS FOR TEXTURIZING YARN Filed April 30. 1959 IN VEN TOR. PIETER VAN DIJK ATTORNEY 3,067,563 METHOD AND APPARgEIlS FOR TEXTURIZING Pieter Van Dijk, Velp, Netherlands, assignor to American Enka Corporation, Enka, N.C., a corporation of Delaware Filed Apr. 30, 1959, Ser. No. 810,142 Claims priority, application Netherlands May 24, 1958 7 Claims. (Cl. 5734) This invention relates in general to the texturizing of thermoplastic yarns and more particularly to an improved system permitting a plurality of yarn passes through a single heater prior to passage into a false twisting device.

In the production of texturized yarn by the system to which this invention pertains, thermoplastic yarn usually is fed from a supply source into a heater and then through a false twister to a suitable withdrawal and/ or collection means. Twist imparted by the false twister backs up through the yarn contained within the heater, and the heater functions to set this twist. Upon removal of twist by passage of the yarn to the opposite side of the twist point there is an inherent tendency caused by heat setting for that twist to return, which produces a bulky or voluminous effect. If the yarn is permitted to cool between the heat setting zone and the twist imparting zone, the tendency to shrink and bulk becomes permanent, all as is well known to this art.

It is obvious that this novelty type yarn may be proatent O duced more economically if higher twisting and heat setn ting speeds can be obtained without deleteriously. atfecting the end product. Various technical diffculties are encountered, however, when higher processing speeds are attempted. The yarn must be twisted a certain minimum number of turns per inch, and the twisted yarn must be maina tained at a certain temperature for a minimum period of time to insure proper heat setting. Moreover, the heat setting temperature is limited by the melting point of the yarn processed, which usually results in an increased time for passage through the heater, rather than increased temperature. An increase in velocity or speed of the running yarn also affects the heat setting stage, and usually must be accompanied with an increased length of yarn exposed to elevated temperature, which heretofore meant that the heater length must be extended if higher speeds were desired.

As a result of the aforesaid speed increases and melting point limitations, heaters have now acquired undesirably large dimensions, which not only raises the cost thereof, but also hampers threading up and'other operations. Moreover, the heater length contributes substantially to the overall height of the machine frame with which the same is associated.

In the past it was felt that heater length could b shortened by guiding yarn one or more passes through the same by the use of reversing rollers or the like. Al-

though these rollers indeedappear to guide the yarn without appreciable tension increase, it has been found that they hinder passage thereover of the false twist. In

other words, reversing means used heretofore prevented V twist from backing up past that point, or locked the twist to the last length of yarn running through the twist setting means. An example of the type reversing means experimented with in the past may be found in US. Patent No. 923,425, particularly FIGURE 5, which issued on June 1, 1909, to Gin et al.

A primary object of the present invention is to provide av texturizing process and apparatus not having disadvantages such as discussed above.

An additional object of this invention is to provide a novel texturizing process and apparatus permitting high MICC speed operation with conventional length twist setting equipment.

Another object of the present invention is to provide a system for threading up a texturizing device enabling a plurality of yarn passes through a twist setting unit while permitting twist back up throughout the length of yarn contained in the unit.

Still another object of this invention is to provide a yarn direction reversing means or guiding system not accompanied by twist lock for use in combination with a false twister-heat setting type texturizing apparatus in order to permit reduction in heater length even at higher false twister speeds.

A conventional yarn texturizing apparatus including a supply source, feed means, twist barrier, twisting device, twist setting unit and withdrawal means may be improved, in accordance with the present invention, by adding guides defining multiple passes of yarn through the twist setting unit, and by providing means for reducing friction or for causing slippage of yarn over these guides, whereby twist imparted by the twist device may travel through every portion of yarn contained in the setting unit back to the twist barrier. If a guide rod is used at the direction reversing points, the slippage may be caused by moving the guide in the direction as the twist or by vibrators, and if rollers are used for reversing the yarn direction, the slippage may be caused by driving the same at a speed in excess of the yarn speed. In either case, the resistance to yarn twisting is lowered sufficiently to permit passage of twist thereover. Consequently, the twisting device produces twist in each length of yarn passing through the setting unit, and this unit accordingly functions as before to set twist, but now in a plurality of lengths. Usually, setting is accomplished by subjecting the twisted yarn to elevated temperature, as explained earlier.

As a result of the presence of the guiding system described above, it is now possible to pass yarn several times along or through the same heating and/or cooling surface, and the yarn will be highly twisted over the whole path in which thermal yarn treatment may occur. Accordingly, in addition to the apparatus mentioned, this invention also relates to an improved method for heating or cooling twisted thermoplastic yarn by passing the samea plurality of times in twisted condition along a known setting surface.

Other objects and advantages will become apparent upon study of the following detailed disclosure taken in conjunction with the accompanying drawings, wherein FIGURE 1 is a side elevational view of a complete yarn texturizing apparatus, modified in accordance with one embodiment of this invention;

FIGURE 2 is an enlarged view of the guide means shown in FIGURE 1;

FIGURE 3 is a detailed elevational view similar to FIGURE 2 but showing a second embodiment of the guide or direction reversing means; and

FIGURE 4 is an elevational view showing .still an- Other modification of the guide system and means for reducing the frictional drag thereof.

In FIGURE 1, one thermoplastic texturizing position is indicated generally by reference numeral 10/. It should be understood that a complete machine will be equipped with a plurality of these units or positions. Yarn 11 is withdrawn from package 12 through pigtail guide 13 by feed means 14, which usually consist of two st el drive rollers and a rubber coated pressure roller. These rollers may be driven by any convenient means, not shown. From the rollers 14, the yarn is passed through a twist barrier or twist lock formed by pressure rollers 15 and fed into the heating unit 16. Heater 16 as illustrated is a narrow tube formed, preferably, from stainless steel and m idi5efi en d \ii t h suitable terminals through which an electrical current gray be passed. The heater serves as a fixation zone Wkierein the false twist is set.

ge siem avs trgssr ametnst aea 22% sources of heat could be em 1 scat AAZT E EQ; s \EILNMJQA :c

From tubular Heater EE QiiH aw, 3L v ":1 2% te art e15 he guide W111 b Ja vtil ates rs ts tite reversing means at each te Xturizmg o rod speed isxorrelated to the twist c tor the; re T 'ii v shown. With attention no aim he rictional drag nornggli resistance to yarn travel reduced, but also the resistance to rotatlon of yarn produced by the twisting operation 1s eliminated so that the twistgijmay run back in the yarn past the guiding system. As a result, twist is imparted to both lengths of yarn within the heater, and ttzsett rrerepera i azu s ee itr-t i' ssztbe aew work heretofore obtaine v saws b t'ffr ti; Wits 11 MST 11d ent passage pa e ggdueed: be my A li e tm es o ler cuss Various other guiding systems may be designed for reversing yarn direction without stopping the twist. For example, the yarn could be passed over two small rotating members disposed at an angle of about 45 with respect to the direction of yarn travel in the heating device. With this arrangement, it is possible to guide yarn in a helical path successively over the two members in such a manner that the resistance to yarn rotation, or twist, would be reduced to zero. Moreover, a flexible tube may be bent through an angle of 180 and then driven about its axis at a speed of revolutions corresponding to the turns per inch imparted by the false twist device. Operation of this embodiment could correspond generally to that of known fatigue testers such as shown in US. Patent No. 2,657,573, with the flexible tubing appearing at element 5.

It is pointed out that, in some instances, it may be desired to cool yarn 11 immediately after heating and twist setting. This unit could be similar to heater 16, but of course would be provided with a cooling medium. These heaters and/or cooling devices may be of various forms. It is possible to construct the same as a flat member, to curve them either longitudinally or transversely, and they may be shaped in the form of a trough or a tube, as shown.

It should also be pointed out that this invention is useful in any type of twist setting operation, whether the twist be false, as illustrated, or positive.

Inasmuch as other modifications will become apparent to those skilled in this art, it is intended that this invention be limited only to the scope set forth in the following claims.

What is claimed is:

'1. A yarn texturizing apparatus comprising a twist device, a twist-set device, means for guiding yarn at least twice through said twist-set device before passage into said twist device, and means for vibrating said guide means to produce slippage between the same and the yarn to reduce the friction therebetween and thereby permit back up of yarn twist over said guide means.

2. Apparatus as set forth in claim 1 wherein said last named means vibrates said guide means in an axial direction thereof,

3. Apparatus as set forth in claim 1 wherein said last named means vibrates said guide means in a radial direction thereof.

4. Apparatus as set forth in claim 1 wherein said last named means vibrates-said guide means both in an axial and in a radial direction thereof.

5. Texturizing apparatus comprising a false wist device for imparting twist to yarn passing therethrough, a heater for setting said twist, means for feeding yarn into said heater and false twist device, a twist barrier for preventing back up of twist into said feeding means, means for guiding said yarn at least twice through said heater before passage into said false twist device, means for vibrating said guide means to produce slippage between the same and the yarn to reduce the friction therebetween and thereby permit back up of twist thereover, and means for withdrawing twist-set yarn from said false twist device.

6. Apparatus as set forth in claim 5 wherein said withdrawing means also imparts a positive twist to said yarn.

7. In a method of texturizing yarn including the steps of twisting yarn and passing the twisted yarn through a fixation zone to set the twist therein, the improvement comprising the steps of guiding said yarn back and forth at least twice through said fixation zone, and vibrating the yarn at each reversal point in order to produce slippage between the same and the yarn to reduce the friction therebetween and thereby prevent twist stop.

References Cited in the file of this patent UNITED STATES PATENTS 270,169 Wilmarth Jan. 2, 1883 2,803,105 Stoddard et a1 Aug. 20, 1957 2,838,903 Sut-ter June 17, 1958 2,863,280 Ubbelohde Dec. 9, 1958 2,951,330 Bouvet Sept. 6, 1960 FOREIGN PATENTS 1,163,346 France Apr. 21, 1958 

